通过 mvvm 将选定项从 wpf 数据网格传递到存储过程

Question

我已经在不使用 MVVM 的情况下实现了这一点：

private void Del_btn_Click(object sender, RoutedEventArgs e)
{
    try
    {
        List<string> cid = new List<string>();
        foreach (DataRowView rw in Xgrid.SelectedItems)
        {

            cid.Add(rw[1].ToString());
            MessageBox.Show("Deleting " + rw[1].ToString());
        }

        foreach (string cq in cid)
        {
            SqlConnection con = new SqlConnection(str);

            con.Open();
            SqlCommand cmd = new SqlCommand("delete_prc", con);
            cmd.CommandType = CommandType.StoredProcedure;
            SqlParameter param1 = new SqlParameter();
            param1.ParameterName = "@Cid";
            param1.SqlDbType = SqlDbType.NVarChar;
            param1.Value = cq;
            cmd.Parameters.Add(param1);
            cmd.ExecuteNonQuery();
        }
    }
    catch (Exception ex)
    {
        MessageBox.Show(ex.ToString());
    }
}

现在我想用 MVVM 来做这件事。

我有customers.cs 模型类，其中包含所有字段。 现在我不知道如何绑定复选框，所以我可以做到这一点。

Xaml 代码：

<DataGrid.RowHeaderTemplate>
    <DataTemplate>
        <Grid>
            <CheckBox   IsChecked="{Binding Path=ViewModelBase.CheckAll, 
                        Mode=TwoWay, UpdateSourceTrigger=PropertyChanged,
                        RelativeSource={RelativeSource FindAncestor,
                        AncestorType={x:Type DataGridRow}}}" Name="delete"/>
        </Grid>
    </DataTemplate>
</DataGrid.RowHeaderTemplate>

<DataGrid.Columns>
    <DataGridTextColumn Header="rowNo." Width="60" Binding="{Binding RowNumber}" IsReadOnly="True">
        <DataGridTextColumn.ElementStyle>
            <Style TargetType="TextBlock">
                <Setter Property="HorizontalAlignment" Value="Center" />
            </Style>
        </DataGridTextColumn.ElementStyle>
    </DataGridTextColumn>
    <DataGridTextColumn Header="CustomerID" Width="80" Binding="{Binding CustomerID}" IsReadOnly="True"></DataGridTextColumn>
    <DataGridTextColumn Header="CompanyName" Width="100" Binding="{Binding CompanyName}"></DataGridTextColumn>
    <DataGridTextColumn Header="ContactName" Width="100" Binding="{Binding ContactName}"></DataGridTextColumn>
    <DataGridTextColumn Header="ContactTitle" Width="100" Binding="{Binding ContactTitle}"></DataGridTextColumn>
    <DataGridTextColumn Header="Address" Width="80" Binding="{Binding Address}"></DataGridTextColumn>
    <DataGridTextColumn Header="City" Width="100" Binding="{Binding City}"></DataGridTextColumn>
    <DataGridTextColumn Header="Region" Width="80" Binding="{Binding Region}"></DataGridTextColumn>
    <DataGridTextColumn Header="PostalCode" Width="100" Binding="{Binding PostalCode}"></DataGridTextColumn>
    <DataGridTextColumn Header="Country" Width="100" Binding="{Binding Country}"></DataGridTextColumn>
    <DataGridTextColumn Header="Phone" Width="100" Binding="{Binding Phone}"></DataGridTextColumn>
    <DataGridTextColumn Header="Fax" Width="100" Binding="{Binding Fax}"></DataGridTextColumn>

</DataGrid.Columns>

那么如何将它与 mvvm 集成。请帮我这样做。

我想知道要在我的视图模型类中定义什么以及执行此操作的绑定路径应该是什么。

Answer 1

在你的 DataGrid 中放一个类似的命令，你需要添加

xmlns:i="http://schemas.microsoft.com/expression/2010/interactivity"

  <DataGrid HorizontalAlignment="Left" VerticalAlignment="Top" Height="103" Width="517">
        <i:Interaction.Triggers>
            <i:EventTrigger EventName="MouseDoubleClick">
                <i:InvokeCommandAction Command="{Binding GetItem}" CommandParameter="{Binding Header,ElementName=id}"/>
            </i:EventTrigger>
        </i:Interaction.Triggers>
   </DataGrid>

并像这样在 ViewModel 中访问命令

  RelayCommand getitem;
    public RelayCommand GetItem
    {
        get
        {
            if(getitem == null)
            {
                getitem = new RelayCommand(p=>Executeyourcommand(p));
            }
            return getitem;
        }
    }


  void Executeyourcommand(object parameter)
    {
        // parameter is your CustomerID
       // do your work here
    }

你的命令助手类

 public class RelayCommand : ICommand
{
    readonly Action<object> execute;
    readonly Predicate<object> canexecute;

    public RelayCommand(Action<object> execute)
        : this(execute, null)
    {

    }
    public RelayCommand(Action<object> Execute, Predicate<object> Canexecute)
    {
        if(Execute == null)
            throw new ArgumentNullException("execute");
        execute = Execute;
        canexecute = Canexecute;
    }
    public bool CanExecute(object parameter)
    {
        if(canexecute == null)
            return true;
        else
            return canexecute(parameter);
    }
    public event EventHandler CanExecuteChanged
    {
        add
        {
            CommandManager.RequerySuggested += value;
        }
        remove
        {
            CommandManager.RequerySuggested -= value;
        }
    }
    public void Execute(object parameter)
    {
        execute(parameter);
    }
}

而且我没有测试代码，我希望这是你正在寻找的